Field of the Invention
The present invention relates to an electronic tester, and in particular to an alternative current (AC) inrush current testing device and method for testing AC inrush current.
Description of Related Art
An inrush current occurs frequently at the moment when the power of an electrical device (such as power supply unit) starts up. At such a moment, an unpredictable and undesirable transient current happens. This may easily induce a noise, and even the power elements of the electrical device or the load connected to the electrical device could be damaged. Therefore, there is a need to test the greatest inrush current accommodation of the electrical device before being used.
However, the testing result is not reliable while the power capacity of an AC power supply of the testing device is small since the test electrical source generated thereby is smaller than the greatest inrush current. In order to overcome the aforementioned problem, an AC power supply having great power capacity to generate a test electrical source equal to or larger than the greatest current can be used. However, the cost of the testing device is largely increased while the power capacity of the AC power supply is increased. Furthermore, the testing device uses a public alternating current (AC) source as the test electrical source may not be sure whether the power supply meets performance standards since the public AC current is unstable and variable, and the measurement of the magnitude of the tested inrush current is not reliable. The testing device must repeatedly measure the power supply to be sure it can withstand the inrush current without damage. This is a time-consuming and imprecise procedure.
What is needed, therefore, is a testing device for testing the inrush current more precisely and without costly repetition.